Question | Answer |
TITRATION METHOD IS? | BURETTE WASHED WITH DISTILLED WATER AND LITTLE OF SOLUTION B. 2. PIPETTE RINSE WITH DISTILLED WATER & SOLUTION A.3. CONICAL FLASK RINSED WITH DISTILLED WATER. |
4. BURETTE FILLED WITH SOLUTION B SOME. THE BURETTE IS READ TO 0.05CM3 AND VOLUME RECORDED. PIPETTE FILLER PIPETTE FILLED WITH SOLUTION - BOTTOM OF MENISCUS ON THE LINE.5. | |
PIPETTE CONTENTS INTO CONICAL FLASK. & FEW DROPS OF INDICATOR IS ADDED.BURETTE SOLUTION ADDED WITH CONSTANT SWIRLING UNTIL | INDICATOR CHANGES COLOUR. BURETTES READ & DIFFERENCE BETWEEN VOLUMES RECORDED CALLED TITRE. |
TITRES NEED TO BE WITHIN.. | 0.2CM3 OF EACH OTHER. THE MEAN IS THEN CALCULATED. |
DIFFERENCE BETWEEN VOLUMES RECORDED CALLED ... | TITRE |
METHYL ORANGE AND PHENOLPHYTHALEIN. METHYL ORANGE ... | (RED ) *IN ACID. YELLOW IN ALKALI , ORANGE IN END. |
BROMOPHENOL IS ... | BLUE YELLOW IN ACID BLUE IN ALKALI GREEN IN END. |
PHENOLPHTHALEIN IS ... | COLOURLESS IN ACID PURPLE IN ALKALI AND PALE PINK IN THE END. |
CALCULATION OF TRITRATION 3 STEPS... | CALCULATE AMOUNT OF MOLES IF REAGENT OF KNOWN CONCENTRATION |
MOLES = CONCENTRATION X VOLUME. STEP 2: | |
UNITS OF CONCENTRATION USE STIOCHIOMETRY TO CALCULATE OTHER MOLES. STEP 3: CALCULATE CONCENTRATION OF OTHER SOLUTION MOLES/VOLUME.NORMALLY ... | MOLDM-3 CAN BE NMOL DM-3 – MEANS NANOMOLES. 1NMOL = 1X 10-9MOL DM-3. |
GDM-3 MULTIPLIES THE MR OF SOLUTE. | |
PPM ... (PARTS PER MILLION). HOW TO CONVERT MOLDM-3 TO GDM-3 ... | CONCENTRATION X MR = GDM-3. |
GDM-3 TO MOLDM-3 .. | .GDM-3 /MR |
BACK TITRATIONS: USED WHEN ... | SUBSTANCE IS INSOLUBLE OR CANNOT BE TITRATED DIRECTLY. |
METHOD OF BACK TIRTRATION ... | WEIGHT A SAMPLE OF SUBSTANCE. ADD EXCESS STANDARD SOLUTION (ACID OR BASE). TITRATE THE EXCESS OF MAKEUP SOLUTION TO 25.0CM3 AND TITRATED PORTIONS OF DILUTED SOLUTION. USED FOR DETERMINING IMPURE CHALK. |
CALCULATION STARTS BY | CALCULATING THE MOLES 2. (CALCULATE THE TOTAL NUMBER OF HCL IN EXCESS) CALCULATION THE MOLES OF OTHER AND X BY 10 TO GET OTHER ONE.(AMOUNT IN EXCESS) 3. CALCULATE THE AMOUNT OF HCL ORIGINALLY TAKEN – C X V = M. |
STOICHIOMETRY OF A REACTION RATIO ...: | STEP 1 CALCULATE MOLES OF ONE REAGENT, CALCULATE MOLES OF SECOND REAGENT. MOLE /MOLES GIVES THE RATIO. |
IS THE CONC KNOWN OF THE STANDARD SOLUTION... | ? YES 250CM3 IS MADE MR AND CONCENTRATION REQUIRED CALC MASS OF SUBSTANCE. MASS IS OBTAINED CALCULATING THE AMOUNT NEEDED IN MOLES. |
THE MAX ERROR WHEN CALCULATING TITRE IS ... | 2 X 0.05= 0.1CM3. IN A TITRE OF 24.00CM3 IS A PERCENTAGE ERROR OF 0.1 X 100/24.00 = 42% TITRATIONS ARE DESIGNED TO GIVE TITRE BETWEEN 20CM3 AND 30CM3 |
WHAT ARE THINGS TO CAUSE ERROR IN TITRATION... | ? POOR TECHNIQUE NOT RINSING BURETTE AND PIPETTE WITH CORRECT SOLUTIONS, GETTING AIR BUBBLES IN STEM OF PIPETTE. OVERSHOOTING THE END POINT ,OVER RUNNING SOLUTION. NOT SWIRLING THE FLASK AFTER EACH ADDITION OF SOLUTION. |
WHY DO ALL GRP1 COMPOUNDS COLOUR IN BUNSEN FLAME ... | COMPOUNDS OF GROUP 1 ELEMENTS ARE SOLUBLE IN WATER. |
WHAT IS USED IN FLAME TEST... | PLATIMUM OR NICHROME WIRE. |
CHECK NICHROME WIRE CLEAN BY ... | DROPPING IN HCL THEN PLACING ON FLAME.(FLAME SHOULDN'T BE COLOURED). |
DIP WIRE IN CONCENTRATED HCL THEN INTO SOME SOLID. PLACE IN HOTTEST PART OF FLAME AND OBSERVE. | |
CHLORIDES ARE USED IN FLAME TEST BECAUSE ... | VOLATILE. |
WHAT COLOUR POTTASIUM IN FLAME TEST ... | LILAC |
WHY IS LIGHT PRODUCED IN FLAME TEST ? | HEAT OF FLAME CAUSED DECOMPOSITION AND PROMOTE ELECTRON INTO EXCITED STATE IN A HIGHER ORBITAL. THE STATE IS NOT STABLE AND ELECTRONS DROPS TO GROUND STATE. |
WHY IS LIGHT PRODUCED IN FLAME TEST ? | ENERGY RELEASED GIVEN OFF AS VISIBLE LIGHT LIGHT OF DIFFERENT WAVELENGTHS. GAPS BETWEEN ENERGY LEVELS NOT THE SAME FOR ALL CATIONS SO AMOUNT OF ENERGY VARIES. HEAT ENERGY CONVERTED TO LIGHT. |
CALCULATION STARTS BY | 4.CALCULATE THE AMOUNT OF HCL THAT REACTED WITH CHALK. AMOUNT TAKEN –AMOUNT OF EXCESS. 5.HENCE CALCULATE THE AMOUNT OF CACO3 IN THE SAMPLE. RATIO IS THE MOLES. 6.CALCULATE PERCENTAGE PURITY : CALCULATE MASS (MOLES X MR) THEN DIVIDE BY MASS AND X 100. |